Controller for a sewing machine



FIG. 1 is a front elevational view of a controller for a sewing machine, showing our new design, the broken lines showing the written indicia is for illustrative purposes only, and forms no part of the claimed design;

FIG. 2 is a rear elevational view thereof;

FIG. 3 is a top plan view thereof;

FIG. 4 is a bottom plan view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a right side elevational view thereof. 

The ornamental design for a controller for a sewing machine, as shown. 